In general, a bill processing apparatus, which is one of the embodiments of the paper sheet processing apparatus, is incorporated into a service device such as a game medium rental machine installed in a game hall, a vending machine or a ticket-vending machine installed in a public space, or the like which identifies the validity of a bill inserted from a bill insertion slot by a user and provides various types of products and services in accordance with a value of the bill having been judged as valid.
For example, Patent Reference 1 discloses a bill processing apparatus comprising a conveyance mechanism to convey a bill inserted into a bill insertion slot and reading means for reading the bill, wherein the bill processing apparatus conveys the bill identified as legitimate as a result of an authenticity judgment of the bill read by the reading means toward a housing part, and returns the bill identified as counterfeit toward the bill insertion slot. Further, this Patent Reference 1 discloses that a pull-out prevention mechanism that prevents the bill from being drawn out toward the bill insertion slot is provided in order not to allow a bill drawing-out activity after reading information of the bill by the reading means. In general, it is reasonable to consider that bills or the like in various kinds of conditions are supposed to be inserted from a bill insertion slot with respect to such a bill processing apparatus. For example, those are bills having a defective leading end portion at the forefront in the insertion direction of the inserted bill and other damages. These bills, even though they are legitimate bills, may be hooked or caught by components, protrusions, depressed portions, and the like of the conveyance mechanism provided in a traveling route when the bills are conveyed, whereby a conveyance failure of the bills may be caused.
[Patent Reference 1] Japanese Unexamined Patent Application Publication No. 2006-302235